18
8935CF — Instruction Manual
Installation
Cabling
Cabling is done on the rear BNCs of the 8935CF-R module illustrated in
Note
Read the precautions for handling fiber optics before making connections to
the fiber optic connectors as described in
.
Figure 10. 8935CF-R Rear Module
Attenuation Requirements
Some shorter length cable runs will require attenuation to prevent over-
driving the receiver causing bit errors to occur on the fiber link. Use the fol-
lowing guidelines for adding attenuation:
•
The 1310nm Dual Transmitter (SFP-1310-SDTX) requires no attenuation
between fiber transmitter and receiver connections at any cable lengths.
•
CWDM devices used with 8939FCA modules for a mux/demux config-
uration (
) with a cable run from 0-12 km (7.5 miles), must be
attenuated by 3 dB between 8939CFA COM ports.
•
All CWDM devices used in a point-to-point configuration with a cable
run from 0-20 km (12.4 miles), must be attenuated by 5 dB between
fiber transmitter and receiver connections.
8543_03
8935CF-R
OUT
OUT
IN
OUT
CH1
IN
1
2
3
4
OUT
CH2
IN
OUT
CH3
IN
OUT
CH4
CH 1 Electrical In
CH 1 Electrical Out
CH 1 Fiber Out
CH 2 Fiber Out
CH 2 Electrical In
CH 2 Electrical Out
CH 3 Electrical Out
CH 3 Electrical In
CH 3 Fiber Out
CH 4 Fiber Out
CH 4 Electrical In
CH 4 Electrical Out
